Core body structure and winding pipe type heat exchanger

Abstract

The utility model discloses a core structure and a winding pipe type heat exchanger, the core structure comprises: a vertically arranged central cylinder, the interior of which is hollow to form an independent channel with an open lower end; the heat exchange tube is spirally wound on the periphery of the central cylinder along the vertical direction; the plate surfaces of the upper distribution plate and the lower distribution plate are oppositely arranged above the central cylinder up and down, the edges of the upper distribution plate and the lower distribution plate are jointed through a side wall, so that a middle pipeline is formed between the upper distribution plate and the side wall, a through hole is formed in the center of the lower distribution plate, and the through hole is in butt joint with the upper port of the independent channel, so that the middle pipeline is communicated with the independent channel; the side wall is provided with an interface; the connecting pipes are hollow, the pipe walls of the connecting pipes can conduct heat, the connecting pipes extend vertically, the connecting pipes are arranged on the upper distribution plate and the lower distribution plate at intervals, lower ports of the connecting pipes are opened in the lower distribution plate and located on the periphery of the through hole, and upper ports of the connecting pipes are opened in the upper distribution plate. The device can be used for condensing media such as tower top gas and the like, and is beneficial to recovery of non-condensable gas.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchanger technology, specifically relating to a core structure and a wound tube heat exchanger. Background Technology

[0002] Conventional vacuum towers have low overhead gas temperatures, making heat recovery difficult. The overhead gas is directly cooled by air and / or water cooling. The condensed liquid phase enters a separate storage tank. The storage tank is equipped with non-condensable gas condensation and recovery systems and a vacuum pumping connection. Please refer to [link to details]. Figure 1 In existing technologies, the temperature of the cooled non-condensable gas is relatively low, which easily generates droplets when it enters the downstream vacuum pump, affecting the pump's operation. Furthermore, existing technologies involve cumbersome processes such as top condensation, separation of condensed non-condensable gas, and vacuuming systems, resulting in significant resistance drops and making it difficult to guarantee the vacuum level at the top of the vacuum tower, or leading to high energy consumption. These issues also result in lower vacuum levels and higher operating temperatures in the vacuum tower, requiring direct heating of the feed material, which often involves high-temperature heat sources, further increasing the energy consumption of the vacuum tower operation.

[0003] Meanwhile, existing equipment for tower top air cooling, such as air-cooled and / or water-cooled condensers, storage tanks, pumps, and condensers above the storage tanks, is numerous, occupies a large area, and has high operating and maintenance costs. Utility Model Content

[0004] The first technical problem to be solved by this utility model is to provide a core structure that facilitates the recovery of non-condensable gas during heat exchange, in light of the current state of the technology.

[0005] The second technical problem to be solved by this utility model is to provide a wound tube heat exchanger with the above-mentioned core structure, so as to be used for condensation heat exchange of the medium to be condensed, such as the top gas of the tower, and to facilitate the recovery of non-condensable gas.

[0006] The technical solution adopted by this utility model to solve the first technical problem mentioned above is: a core structure, comprising:

[0007] The central tube is set vertically, and its interior is hollow, forming an independent channel with an open bottom.

[0008] Heat exchange tubes are spirally wound around the outer circumference of the central cylinder in a vertical direction;

[0009] Its characteristic is that it also includes:

[0010] An upper distribution plate and a lower distribution plate are arranged one above the other above the central cylinder, with their edges joined by side walls to form an intermediate pipeline between them and the side walls. The lower distribution plate has a through hole in its center, which connects to the upper port of the independent channel to make the intermediate pipeline communicate with the independent channel. The side wall has an interface.

[0011] Multiple hollow, heat-conducting, vertically extending connecting pipes are arranged at intervals on the upper and lower distribution plates. The lower port of each connecting pipe opens onto the lower distribution plate and is located around the through hole, while the upper port of each connecting pipe opens onto the upper distribution plate.

[0012] In use, the shell-side medium, such as the medium to be condensed, flows downward through the connecting pipes and is evenly distributed in the space below the lower distribution plate, thereby exchanging heat with the tube-side medium, such as the cold source, in the heat exchange tubes. After heat exchange, the shell-side medium, such as the non-condensable gas in the medium to be condensed, enters the central cylinder and intermediate pipes sequentially through the lower port of the central cylinder. Because the pipe walls are thermally conductive, the shell-side medium in the intermediate pipes can exchange heat with the shell-side medium in the connecting pipes before being output from the interface. This allows the invention to utilize the heat of the shell-side medium in the connecting pipes to heat the non-condensable gas in the intermediate pipes, preventing the non-condensable gas from carrying uncondensed gas phase and generating droplets that could affect the operation of downstream equipment (such as vacuum pumps) connected to the interface, thus facilitating the recovery of non-condensable gas. In other words, this invention utilizes the heat of the shell-side medium before heat exchange to act on the shell-side medium after heat exchange and achieves uniform distribution of the shell-side medium, demonstrating significant technical advantages.

[0013] Preferably, the central cylinder has multiple fins spaced vertically inside, each fin extending obliquely upward from the inner wall surface of the central cylinder. The fins improve the removal of non-condensable gases and enhance the bending strength of the central cylinder.

[0014] Preferably, a drain hole is provided at the connection between the fins and the inner wall of the central cylinder to allow condensate to flow downwards.

[0015] Preferably, the fins are positioned relatively close to the lower end of the central cylinder.

[0016] Furthermore, the lower port of the connecting pipe is located below the lower distribution plate, and the upper port of the connecting pipe is located above the upper distribution plate.

[0017] In the above embodiments, preferably, the wall of the central cylinder is a heat-conducting wall. Since heat exchange tubes are arranged around the outer periphery of the central cylinder, the cooling capacity of the cooling medium inside the heat exchange tubes can be transferred to the interior of the central cylinder through the cylinder wall, thereby further condensing the non-condensable gas inside the central cylinder and improving the liquid removal effect of the non-condensable gas.

[0018] The technical solution adopted by this utility model to solve the second technical problem mentioned above is as follows: a wound tube heat exchanger, including a shell-side cylinder, characterized in that it also has a core structure as described above, the core structure is disposed in the shell-side cylinder, and the side wall is a part of the side peripheral wall of the shell-side cylinder, the upper part of the shell-side cylinder is provided with a shell-side inlet, the shell-side inlet is located above the upper distribution plate and is connected to the upper port of the connecting pipe.

[0019] Compared with the prior art, the advantages of this utility model are as follows: By setting up the upper distribution plate, the lower distribution plate, and the connecting pipes, during heat exchange, the shell-side medium, such as the medium to be condensed, can flow downward through each connecting pipe and be evenly distributed in the space below the lower distribution plate, thereby exchanging heat with the tube-side medium in the heat exchange tube, such as the cold source. After heat exchange, the non-condensable gas in the shell-side medium, such as the medium to be condensed, can enter the central cylinder and the intermediate pipeline sequentially through the lower port of the central cylinder. Since the pipe wall of the connecting pipe can conduct heat, the shell-side medium in the intermediate pipeline can exchange heat with the shell-side medium in the connecting pipe and then be output from the interface. Thus, this utility model can use the heat of the shell-side medium in the connecting pipe to heat the non-condensable gas in the intermediate pipeline, so as to prevent the non-condensable gas from carrying uncondensed gas phase and generating droplets when output from the interface, which would affect the operation of downstream equipment (such as vacuum pump) connected to the interface, thereby facilitating the recovery of non-condensable gas. This invention can utilize the heat of the shell-side medium before heat exchange to act on the shell-side medium after heat exchange, and can achieve uniform distribution of the shell-side medium, thus having positive technical effects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a vacuum tower top condenser reflux system in the prior art;

[0021] Figure 2 This is a schematic diagram of the vacuum tower top condenser reflux system according to an embodiment of the present invention;

[0022] Figure 3 This is a longitudinal sectional view of the wound tube heat exchanger according to an embodiment of the present invention;

[0023] Figure 4 for Figure 3 Enlarged view of section A;

[0024] Figure 5 for Figure 4 Top view of the middle fin;

[0025] Figure 6 for Figure 4 A schematic diagram of the middle fin in direction B. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] like Figures 2-6 The image shows a preferred embodiment of the core structure and wound tube heat exchanger of this utility model. This wound tube heat exchanger can be used for the condensation of overhead gas in a vacuum tower. This embodiment is described in conjunction with a vacuum tower, as follows:

[0028] Vacuum tower 1 is existing technology.

[0029] The wound tube heat exchanger 2 is vertically positioned above the vacuum tower 1. It comprises a shell-side cylinder forming a shell side 22, a central cylinder 20 vertically disposed within the shell-side cylinder, and heat exchange tubes spirally wound around the outer circumference of the central cylinder 20. The heat exchange tubes form a tube side 21, which has two sides: a first tube side 211 and a second tube side 212. The first tube side inlet 211a is used for raw material input, and the first tube side outlet 211b is connected to the vacuum tower 1 via a pipeline. The second tube side inlet 212a is used for external cold source input, and the second tube side outlet 212b is used for cold source output after heat exchange. Simultaneously, the top of the shell-side cylinder is provided with a shell-side inlet 22a for vacuum tower top gas input, and the shell-side inlet 22a is connected to the top outlet of the vacuum tower 1 via a pipeline. The bottom space of the shell-side cylinder is a chamber 220 for receiving condensate after the top gas of the vacuum tower has condensed. Chamber 220 is located below the central cylinder 20. At the bottom of chamber 220 is a shell-side liquid phase outlet 22b for condensate output. Shell-side liquid phase outlet 22b is connected to the vacuum tower 1 and downstream equipment via two pipelines, respectively. A valve for controlling the flow rate is installed on the pipeline connecting shell-side liquid phase outlet 22b to the vacuum tower 1. Meanwhile, the central cylinder 20 has a hollow interior forming an independent channel. The lower port of this independent channel is located above chamber 220 to allow non-condensable gases to pass upwards. The upper port of this independent channel is connected via an intermediate pipeline 26 to an interface 22c on the upper side wall of the shell-side cylinder. This interface 22c serves as a shell-side gas phase outlet connected to the vacuum pump.

[0030] In this embodiment, the shell-side cylinder is provided with an upper distribution plate 261, a lower distribution plate 262, and a plurality of connecting pipes 264 (the upper distribution plate 261, the lower distribution plate 262, the connecting pipes 264, the aforementioned central cylinder 20, and the heat exchange tubes constitute the core structure of this embodiment). The upper distribution plate 261 and the lower distribution plate 262 are arranged one above the other above the central cylinder 20, and their edges are connected to the side wall of the shell-side cylinder, so that the two and the side wall of the shell-side cylinder form the aforementioned intermediate pipe 26. The lower distribution plate 262 has a through hole 263 in the center to connect the intermediate pipe 26 with the independent channel inside the central cylinder 20. The connecting pipe 264 is hollow inside and its wall is heat-conducting. The connecting pipes 264 are arranged at intervals in the horizontal direction and vertically inserted into the upper distribution plate 261 and the lower distribution plate 262. The upper port of the connecting pipe 264 is located above the upper distribution plate 261, and the lower port of the connecting pipe 264 is located below the lower distribution plate 262 and outside the through hole 263. This allows the vacuum tower top gas entering from the shell side inlet 22a to flow downward through the connecting pipe 264 to the space below the lower distribution plate 26 and exchange heat with the cold medium in the heat exchange tube and condense. The condensate after heat exchange is collected in the chamber 220, and the non-condensable gas enters the central cylinder 20 from the lower port.

[0031] The non-condensable gas entering the central cylinder 20 may carry uncondensed gas phase. To further remove liquid from the non-condensable gas entering the central cylinder 20, the cylinder wall of the central cylinder 20 is a thermally conductive wall. Multiple fins 201 are vertically spaced inside the central cylinder 20, positioned relatively close to the lower end of the central cylinder 20. Each fin 201 extends obliquely upward from the inner wall surface of the central cylinder 20, and a leakage hole 202 is provided at the connection between each fin 201 and the inner wall surface of the central cylinder 20 to allow liquid to flow down and be collected in the chamber 220. The non-condensable gas passing through the fins 201 continues to flow upward into the intermediate pipe 26. At this point, the vacuum tower top gas through the connecting pipe 264 preheats the non-condensable gas in the intermediate pipe 26 to prevent the formation of droplets when the non-condensable gas carries uncondensed gas phase into the vacuum pump. In this embodiment, since the fins 201 are positioned relatively close to the lower end of the central cylinder 20, and the lower end of the central cylinder 20 is relatively close to the tube inlet, the cold medium with a lower temperature can condense and remove the non-condensable gas in the central cylinder 20.

[0032] The wound tube heat exchanger in this embodiment replaces the original top condenser (air-cooled + water-cooled), storage tank, reflux pump, and distillate pump, resulting in reduced equipment investment and significant energy savings. The wound tube heat exchanger utilizes the central cylinder as the space for gas-liquid separation, which helps to reduce equipment size and height, thereby reducing pressure losses, increasing the column's vacuum level, and reducing the energy consumption of the vacuum pump.

[0033] In the specification and claims of this utility model, terms indicating direction, such as "upper," "lower," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0034] The term "vertical" is also used in the specification and claims of this utility model, meaning basically along the up and down direction, and is not limited to just the vertical direction, but can also be slightly deviated from the vertical direction.

Claims

1. A core structure, comprising: The vertically arranged central tube (20) has a hollow interior forming an independent channel with an open bottom; Heat exchange tubes are spirally wound around the outer circumference of the central cylinder (20) in a vertical direction; Its features It also includes: The upper distribution plate (261) and the lower distribution plate (262) are arranged above the central cylinder (20) with their surfaces facing each other. The edges of the two plates are joined by the side wall to form an intermediate pipe (26) between the two plates and the side wall. The lower distribution plate (262) has a through hole (263) in the center. The through hole (263) is connected to the upper port of the independent channel to make the intermediate pipe (26) communicate with the independent channel. The side wall has an interface (22c). Multiple hollow, heat-conducting, vertically extending connecting pipes (264) are arranged at intervals on the upper distribution plate (261) and the lower distribution plate (262). The lower port of each connecting pipe (264) opens into the lower distribution plate (262) and is located around the through hole (263). The upper port of each connecting pipe (264) opens into the upper distribution plate (261).

2. The core structure according to claim 1, characterized in that: The central cylinder (20) is provided with a plurality of fins (201) spaced vertically along its inner edge, and each fin (201) extends obliquely upward from the inner wall surface of the central cylinder (20).

3. The core structure according to claim 2, characterized in that: A leakage hole (202) is provided at the connection between the fin (201) and the inner wall of the central cylinder (20).

4. The core structure according to claim 2, characterized in that: The fins (201) are positioned relatively close to the lower end of the central cylinder (20).

5. The core structure according to claim 1, characterized in that: The lower port of the connecting pipe (264) is located below the lower distribution plate (262), and the upper port of the connecting pipe (264) is located above the upper distribution plate (261).

6. The core structure according to any one of claims 1 to 5, characterized in that: The wall of the central cylinder (20) is a heat-conducting wall.

7. A wound tube heat exchanger, comprising a shell-side cylindrical body, characterized in that... It also has a core structure as described in any one of claims 1 to 6, the core structure being disposed within the shell-side cylinder, and the sidewall being a portion of the side peripheral wall of the shell-side cylinder, the upper part of the shell-side cylinder having a shell-side inlet (22a), the shell-side inlet (22a) being located above the upper distribution plate (261) and communicating with the upper port of the connecting pipe (264).

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